Typically, photographic materials include silver halide emulsion layers sensitive to the three primary colors of red, green and blue colors of light. A dye image is formed by three kinds of color formers (i.e., couplers) contained in the emulsion layers which are developed in relation with complementary colors to colors sensitive to these layers, respectively. Namely, a dye image is formed by subtractive color photography.
The dye image obtained by processing such photographic materials is generally composed of an azomethine dye or an indoaniline dye formed by the coupling reaction of the couplers with the oxidants of aromatic primary amine developing agents. However, the thus obtained color photographic image is not always stable against exposure to light or moisture and heat. For example, when the image is exposed to light over a long period of time, or stored under high temperature and humidity conditions, the dye image becomes faded or discolored.
The fading or discoloration of the dye image is a serious defect in recording materials. To solve this problem, the art has turned to couplers capable of providing dyes having high fastness or to color mixing inhibitors. Further, the use of ultraviolet light absorbers has been proposed to prevent the image from being deteriorated by ultraviolet light.
The use of color mixing inhibitors has been remarkably effective in preventing the image from being deteriorated. For example, hydroquinones, hindered phenols, catechols, gallic esters, aminophenols, hindered amines, chromanols, indanes, and ethers or esters obtained by silylating, acylating or alkylating the phenolic hydroxyl group of these compounds and metal complexes are conventionally added.
While these compounds have effectively prevented the dye image from being faded or discolored, they are still considered insufficient to meet the requirements of customers who require a higher image quality. Moreover, these compounds can introduce certain disadvantages. Such disadvantages include a change in hue, fogging, a failure in dispersion, and crystallite formation after the coating of the emulsions. Accordingly, on a whole, these compounds are not considered to provide excellent effects as photographic additives.
Certain phenolic compounds having a specific substituent group in the molecule as well as derivatives thereof are known as image deterioration inhibitors. Further, hydrazide compounds and hydroxylamine compounds are known as antifading agents.
These compounds can prevent fading from occurring. However, these compounds are insufficient to meet the requirements of imparting high fastness to the image. Further, some of these compounds have introduced certain disadvantages. These disadvantages include a change in hue, great coloration of white ground, color formation (hereinafter referred to as fog) in unexposed area, and the inhibition of the development of the couplers. Thus, it is clear that these compounds often have an adverse effect on photographic characteristics.
U.S. Pat. No. 4,252,893 discloses specific phenolic compounds as antifogging agents. The compounds have an antifogging effect, but do not provide a sufficient antifading effect.